在 Flutter 中将数据保存到 Firebase 实时数据库答案

【问题标题】：Save Data to Firebase Realtime Database in Flutter在 Flutter 中将数据保存到 Firebase 实时数据库
【发布时间】：2020-10-10 16:41:12
【问题描述】：

在我的代码中，用户通过电话身份验证登录。登录后，我想获取用户的用户 ID，并将其连同其个人详细信息一起添加到 Firebase 数据库中。

但是当我这样做时，数据库中的路径是直接的，而不是应该通过第一个 UserId 然后在个人详细信息下。我还提供了带有数据库输出的图像。

代码：

import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:flutter/cupertino.dart';
import 'package:udharibook/Screens/SignInPage.dart';
import 'package:udharibook/Screens/dashboard.dart';

class AuthService  {
  String UserId ='';
  final DBRef = FirebaseDatabase.instance.reference().child('Users');
  final FirebaseAuth _auth = FirebaseAuth.instance;
  handleAuth(){
    return StreamBuilder(
      stream: FirebaseAuth.instance.onAuthStateChanged,
      builder: (BuildContext, snapshot){
        if(snapshot.hasData){
          getCurrentUser();
          writeData();
          return DashboardPage();
        }
        else {
          return SignIn();
        }
      },
    );
  }
  getCurrentUser() async{
    final FirebaseUser user = await _auth.currentUser();
    final uid = user.uid;
    // Similarly we can get email as well
    //final uemail = user.email;
    UserId = uid;
    print('User ID:  '+UserId);

    //print(uemail);
  }

  void writeData(){
    DBRef.child(UserId).set({
      'id':'ID1',
      'Name':'Mehul Jain',
      'Phone':'8856061841'
    });
  }

  signOut(){
    FirebaseAuth.instance.signOut();
  }

  signIn(AuthCredential authCreds){
    FirebaseAuth.instance.signInWithCredential(authCreds);
  }

  signInWithOTP(smsCode,verId){
    AuthCredential authCreds = PhoneAuthProvider.getCredential(
        verificationId: verId,
        smsCode: smsCode
    );
    signIn(authCreds);
  }
}

数据库图片

【问题讨论】：

标签： firebase flutter dart firebase-realtime-database firebase-authentication

【解决方案1】：

getCurrentUser() 方法是异步方法，因此在调用 writeData() 方法之前不确定您的 userId 是否具有值。

所以您可以在完成writeData() 方法后调用writeData()，即：

import 'package:firebase_auth/firebase_auth.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:flutter/cupertino.dart';
import 'package:udharibook/Screens/SignInPage.dart';
import 'package:udharibook/Screens/dashboard.dart';

class AuthService  {
  String UserId ='';
  final DBRef = FirebaseDatabase.instance.reference().child('Users');
  final FirebaseAuth _auth = FirebaseAuth.instance;
  handleAuth(){
    return StreamBuilder(
      stream: FirebaseAuth.instance.onAuthStateChanged,
      builder: (BuildContext, snapshot){
        if(snapshot.hasData){
          getCurrentUser();
          //call writeData() from inside the above method
          return DashboardPage();
        }
        else {
          return SignIn();
        }
      },
    );
  }
  getCurrentUser() async{
    final FirebaseUser user = await _auth.currentUser();
    final uid = user.uid;
    // Similarly we can get email as well
    //final uemail = user.email;
    UserId = uid;
    print('User ID:  '+UserId);
    //print(uemail);
    
    //Here you add the method calling 
    writeData();
  }

  void writeData(){
    DBRef.child(UserId).set({
      'id':'ID1',
      'Name':'Mehul Jain',
      'Phone':'8856061841'
    });
  }

  signOut(){
    FirebaseAuth.instance.signOut();
  }

  signIn(AuthCredential authCreds){
    FirebaseAuth.instance.signInWithCredential(authCreds);
  }

  signInWithOTP(smsCode,verId){
    AuthCredential authCreds = PhoneAuthProvider.getCredential(
        verificationId: verId,
        smsCode: smsCode
    );
    signIn(authCreds);
  }
}

【讨论】：

【解决方案2】：

尝试以下方法：

  void writeData() async{
    final FirebaseUser user = await _auth.currentUser();
    final uid = user.uid;
    DBRef.child(uid).set({
      'id':'ID1',
      'Name':'Mehul Jain',
      'Phone':'8856061841'
    });
  }

删除getCurrentUser()方法并在writeData()中检索uid

【讨论】：